Definition of Postpolio syndrome (PPS)

Postpolio syndrome (PPS): Persons who have had polio may develop newly progressive fatigue, pain, and weakness 15 or more years after recovery from poliomyelitis. In some cases, muscle atrophy (muscle wasting) also occurs as part of PPS. In most cases, however, new symptoms are not due to progression of old polio but to a superimposed second condition, such as diabetes, a vertebral disk problem, or degenerative joint disease.

PPS is a constellation of symptoms and signs that appear from 15 to 40 years after the initial polio infection, and at least 10 years after what was thought to be recovery from polio. In the epidemics of the 1940's, 50's, and early 60's, about 1,630,000 Americans were struck by polio and 440,000 of the survivors suffer the effects of PPS.

The typical features of PPS include unaccustomed weakness, muscle fatigue, central fatigue, pain, breathing problems, swallowing difficulties, sleep disorders, muscle twitching (fasciculations), and gastrointestinal problems. The muscle problems in PPS can occur in previously-affected muscles, or in muscles that were thought not to be affected at the onset of polio. The onset of PPS is usually gradual, but it is sometimes abrupt, with major loss of function suffered over several months or a couple of years. This process often seems to start after a physical or emotional trauma, an illness, or accident. Complications of PPS may include neuropathies, nerve entrapments, arthritis, scoliosis, osteoporosis and, sometimes, post-
polio muscular atrophy (PPMA).

Diagnosis is made by history, by clinical findings, and by ruling out other diseases that may mimic PPS. There are no specific tests to provide unquestionable confirmation of the diagnosis of PPS. The general rule is that those who were most seriously affected by the virus at initial onset and made the best recovery come to suffer the worst PPS symptoms years later. No clearcut cause for PPS has been found. There is known to be a failure at the neuromuscular junction. One idea is that nerves and muscles that have had to overwork prematurely fail, but this is unproven. There is also known to be impairment in the production of certain hormones and neurotransmitters, but whether these changes are the cause of PPS or the effect of it is unknown.

Polio survivors tend to be hard-driving, type-A personalities, as compared to nondisabled control subjects-and the more driven polio survivors tend to have more PPS symptoms.

Treatment may include slowing down to conserve strength and energy. Musculoskeletal problems can sometimes be helped by antiinflammatory or pain medications, with or without surgical procedures.